System of electric lighting



(No Model.)

T. A. EDISON.

SYSTEM OF ELECTRIC LIGHTING.

. No. 328,573. Patented Oct. 20, 1885.

AT TE 8 'I: INVENT OB:

n. PETERS. PhomLilhqr-pbor. want- 1w. o. c.

UNITED STATES PATENT OFFICE,

THOMAS A. EDISON, OF MENLO PARK, NEV JERSEY.

SYSTEM OF ELECTRIC LIGHTING.

SPECIFICATION forming part; of Letters Patent No. 328,573, dated October 20, 1885.

Application filed October 2, 1884. Serial No. 144,544. (No model.)

To all whom it may 0077 0677];

Be it known that I, THOMAS A. EDIsoN, of Menlo Park, in the county of Middlesex and State of New Jersey, have invented a certain new and useful Improvement in Systems of Electric Lighting, (Case No. 630,) of which the following is a specification.

The object I have in view is to utilize incandescing electric lamps upon high-tension circuits for street-lighting, or for other purposes where great economy in conductors is desirable and a high-tension current is not objectionable.

My invention relates, first, to the arrangement of the incandescing electric lamps in series in a high-tension circuit, with peculiar automatic cut-out mechanisms for the lamps, which maintain the continuity of the circuit when the carbon conductor of a lamp breaks; and, second, to the arrangement for a system of several circuits, all the circuits being taken from a common source of supply, and means being provided for maintaining constant the relative resistances of the several circuits.

WVith regard to the first part of my invention, I employ at each lamp of the series in the circuit an electro-magnetic cutout with a localizing shunt-circuit around the lamp,which is constantly closed to prevent the action of all the cut-outs when one acts. I may use a differential cutout, the localizing shunt forming the high-resistance coils of the magnet. The difierential cut-out is a differentially-wound electro-magnet or solenoid, one set of coils being directly in the line in series with the lamps and the other set of coils being in a constantlyclosed shunt (the localizing circuit) around the particular lamp the mechanism is designed to cut out. This magnet or solenoid acts upon an armature or core, closing,when the lamp-carbon breaks, a shunt around the broken lamp. The shunt is maintained in any of the known ways by a mechanical locksuch as a spring-catch or trigger-or by an electrical lock, throwing into circuit coarse-wire coils, which maintain the magnetism and hold the shunt closed. In these general respects the differential automatic cutout for an incandescing electric lamp does not differ, except in its application,

from similar mechanisms used in connection with arc-lamps,- but an automatic cutout for incandescing electric lamps depending for its proper operation upon other conditions than the similar mechanism for arclamps, the construction and adjustment of the devices are necessarily different. In an arc-light cut-out the cutout may operate when the arc becomes abnormally long, and while there is still current in both sets of coils of the differential magnet or solenoid; but in my cut-out for incandescing electric lamps the operation is designed to take place only when the lamp-carbon is broken and there is a total cessation of current in one set of the differential coils. The incandescing carbon conductor of the lamp changes its resistance rapidly under changes in temperature, the lowering of the temperature producing an increase in its resistance. This may occur at any time by the flickering of the lamps from any causesuch as the cutting out of a lamp-or the temperature of each lamp may be decreased and the resistance increased when the load is too great for the dynamo or dynamos supplying the current. It is evident, also, that this peculiar property of the incandescing carbon conductors might cause all the cut-outs to act when the dynamo is first started up. To overcome these difficulties I make the retracting-spring of sufficient strength and strain it to the propor point, so that the armature or core will not be moved, except upon a complete cessation of the current through that set of coils of the differential magnet orsolenoid which is in the line. The shunt-circuit which is closed by this cut-out mechanism may include another lamp, or a resistance in other form equal to the broken lamp, or where the current is regulated at the source of supply this shunt will have practically no resistance at all.

The localizing shunt-circuit, which is constantly closed around each lamp, instead of including one set of coils of the differential magnet, may be asimple resistance. The cutout will then be a magnet whose armaturelever closes the cut-out shunt at its back point. The parts will be constructed and adjusted so that the magnet will attract the armature and keep the shunt open when there is any current in the magnet, and will not permit the shunt to close or remain closed except upona total cessation of current in the magnctcoils.

In carrying out the second part of my invention I provide a source of electrical supply composed of one or more dynamo'electric machines, the machines (it more than one) being connected to common or omnibus conductors in the station. The machine (or each machine, it more than one is employed) is provided with means,either manual or automatic, for varying the current gcner ted by it. is is preferably an adjustable resistance in are field-magnet circuit of the machine, which is a derived circuit taken from the armature ol' the machine. From this common source of supply is run two or more lightingcircuits, each containing a number or incandescing electric lamps having cut-out mechanisms. In a system of this character it is essential that the relative resistances of the several circuits taken from the common source of supply should be maintained, so that the current will be properly distributed between the two or more circuits, and each will receive the right number of amperes of current to maintain the lamps atnormal incandescence. This may be done in several ways, all of which come within the scope of the broad invention here ,inafter claimed. The cut-out for each lamp may be arranged to throw in an equivalent resistance, whether another lamp or not; or the regulation can be performed by throwing resistances into the circuits at the central station.

Q A is a d namoclectric machine lttilll? 'ltfl The last way is covered specifically by an ap plication for patent of even date herewith, Serial No. 1%,545, and hence is not claimed herein, except as it comes within the scope of the broad invention hereinafter claimed.

The circuits,instead ol'beiug simple circuits, may be compensating circuitsa construction which is also covered specifically by an application of even date herewith, Serial No. 144,546.

In the accompanying part hereof, Figure 1 is a view, orinciually in diagram and partially developed, ill ing a system embodying my inr l a similar view of a dynamoelect and a single circuit supplied ther a a view of a modified form of cutout, 4 a view of the cut ont showing e lock.

drawings, forming a field-circuit derived from i z n c including an adjustable resistance, machine supplies iucandescing elect L 1), arranged in series.

B is a diiterentially-wound electro-magnct, forming the operating element ot the cutout at each lamp. "his magnet has one set of coils,'a, located in the line in series with the lamps, while its othe set ot'e 'l. ashunt constantly closed around ti forming a localizing circuit or the The armature-lever G closes a closed by a spring-lock, e, 1 by an electrical lock termed by magn c in the shunt-circuit, Fi g. The retractingspring d of the armature-lever is adjusted to produce the effect described. The shunt closed by lever C may have practically no resistance, as in 2, or it may include a resistance, 0', equal to a lamp or an extralanip, L, Fig. 1.

The circles D are intended to represent lamps and cutouts, one being developed for each circuit.

In Sthe cutout is composed of a magnet, E, in series with all the lamps, and a consiantlyelosed shunt-circuit around the lamp and magnet containing a resistance, r. The magnet keeps the cutout shunt open while L is burning, no change in resistance of L, due to changes in temperature, serving to weaken E enough to close the cut-out shunt.

in starting up the plant the cut-out shunts will be opened, provided he resistance r or lamp L oi Fig. l is used, otherwise a small resistan 1e, 2*, in thecut-out shunt is employed In Fig. 1 two circuits, 1 2 and 3 at, are taken from the same machine, and the relativeresistauces of the circuits are maintained by the operation which takes place at the cut-outs, resistances equal to the lamps cut out or other lamps being thrown into ci *cuit as the lamps break.

What I claim is- 1. The combinatiomwith ineandescing elcctric lamps arranged in series, of automatic cutout mechanisms l'orthe several separate lamps, (including a localizing constantly-closed shunt around each lamp,) maintaining the continuity of the circuit as the incandescing conductors of the lamps break, substantially as set forth.

2. The combination, withincandcscing elec tric lampsarranged in series, of differentiallywound magnets or solenoids closing shuntcircuits around the lamps as they are broken, one set of coils of each dili'crcntial magnet or solenoid being in the main circuit and the other of coils being in a constantly-closed ,1 L around the lamp, and mechanical or electrical locks .l'orholding the shunts closed, substantially as set forth.

3. The combination, with an incandescing clectriclamp, of a magnet in series therewith controlling a cutout shunt, and constructed and adjusted, substantially as described, to permit the same to be closed only alter a total. cesation of currentin the coils of said magnct,and not being aii'ectcd by changes in resistance of the incandescing conductor, and a constantlyclescd sount-cireuit around said lamp, and

substanaffected by changes in resistance of the incanadjusted to act only upon a complete cessadescing conductor, substantially as set forth. tion of current in the set of coils in series with 5. The combination, with an incandescing the lamp, and not to be aifected by changes in electric lamp, of a differentially-Wound magresistance of the incandescing conductor, sub- I 5 5 net or solenoid having one set of coils in sestantially as set forth.

riestherewith and the other set in a constantly- This specification signed and witnessed this closed shunt around said lamp and .the first 12th day of September, 1884. set, an armature or core and retractor acting THOS. A. EDISON. to close a shunt around the lamp, and a me- Witnesses:

1o chanical or electrical lock for keeping said WM. H.'MEADOWOROFT,

shunt closed, the parts being constructed and PAUL D. DYER. 

